NeoCharts:
Trade from charts.

class MyController implements ChartInterface {
  @override
  String get storageKey => 'user_${currentUser.id}';

  @override
  Future<String> loadData({
    required String symbolId,
    required int from,
    required int to,
  }) async {
    // fetch OHLC bars, return as JSON
  }
}

// mount the chart:
NxtChartPage(dataProvider: MyController());